Fiber optic technology is used in a variety of applications, such as, for example, for telecommunications and in environmental sensors. Conventionally, a fiber optic application system may, for example, include a light source, a light detector, various optical components, such as one or more beamsplitters, filters, isolators, modulators, and transducers, and various lengths of optical fiber interconnecting these devices to each other. During operation, the light source generates an optical signal that propagates through the optical fiber and components, conveying information to the detector by means of its intensity, polarization state, or relative phase. Disturbances in the optical fiber that alter these characteristics of the signal may introduce errors in the transmitted information.
Components of such systems are often located in environments at pressures above or below standard atmospheric pressure. To maintain such a pressure environment inside a vessel containing the system components, the optical fiber passes through and is sealed to the wall of the vessel. Conventionally, this is accomplished by including a sealing device in the optical circuit that comprises a length of optical fiber sealed into a ferrule, or body, that is in turn sealed to the wall of the pressure vessel.
Although these seals are useful, they can suffer from certain drawbacks. For example, if the optical fibers of the sealing device and the other components of the optical circuit are not substantially identical, the intensity, polarization state, or relative phase of the transmitted light may be degraded, which may comprise the operation of the system. Additionally, conventional sealing devices may be relatively costly, and may require substantial labor to install them in the pressure vessel and in the optical circuit. Once installed, optical fibers joined to a conventional sealing device may not be moved further into or out of the pressure vessel. Moreover, because the body of a conventional sealing device is relatively large compared to the optical fiber itself, the number of fibers that can be sealed in a limited area of the pressure vessel wall is restricted.
Accordingly, it is desirable to have a low-cost device for hermetically sealing an optical fiber to the wall of a pressure vessel that removes the possibilities of optical incompatibitilies. Additionally, it is desirable reduce the installation costs of such a device. Furthermore, it is desirable to be able to seal multiple optical fibers in a small area of the pressure vessel wall. Other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.